The Intelligent Instant Message Filter program helps protect your Microsoft® Office Live Communications Server deployment against the spread of the most common forms of virus with minimal degradation to the user experience.
The Intelligent Instant Message Filter program is a managed program that can be installed on the following Live Communications Server roles:

Live Communications Server 2005 with SP1, Standard Edition

Live Communications Server with SP1, Enterprise Edition

Live Communications Server with SP1, Access Proxy

Live Communications Server with SP1, Proxy Server

Live Communications Server with SP1 is the minimum version required. The Intelligent IM Filter is not supported on Live Communications Server 2005 without SP1.
The Intelligent Instant Message Filter program enhances the functionality of the IMFilter program, which is installed by default on all Live Communications Servers with SP1, by providing the following: